RAC FINAL EXAM AND PRACTICE
EXAM QUESTIONS 2024 ACTUAL
EXAM COMPLETE 400 QUESTIONS
WITH DETAILED VERIFIED ANSWERS
(100% CORRECT ANSWERS)
/ALREADY GRADED A+
1. What is the primary function of the evaporator in a
refrigeration system?
A) To absorb heat from the surrounding air
B) To condense refrigerant vapor into liquid
C) To compress refrigerant gas
D) To reduce the temperature of the compressor
Answer: A) To absorb heat from the surrounding air
Explanation:
The evaporator absorbs heat from the surrounding air and
uses it to evaporate the liquid refrigerant, turning it into
vapor. This phase change is essential for cooling, as it
lowers the temperature of the space being cooled.
2. Which refrigerant is commonly used in residential
air conditioning systems today?
,A) R-22
B) R-12
C) R-410A
D) R-134a
Answer: C) R-410A
Explanation:
R-410A is widely used in modern residential air
conditioning systems due to its environmental benefits
and higher efficiency compared to older refrigerants like
R-22, which has been phased out due to its ozone
depletion potential.
3. In a refrigeration system, what component is
responsible for raising the refrigerant's pressure and
temperature?
A) Evaporator
B) Condenser
C) Compressor
D) Expansion valve
Answer: C) Compressor
Explanation:
The compressor increases the pressure and temperature of
the refrigerant gas. This process is crucial because it
,allows the refrigerant to release heat when it reaches the
condenser.
4. Which of the following is a potential cause of high
head pressure in a refrigeration system?
A) Low refrigerant charge
B) Dirty condenser coils
C) Blocked expansion valve
D) Malfunctioning evaporator fan
Answer: B) Dirty condenser coils
Explanation:
Dirty condenser coils prevent the refrigerant from
releasing heat effectively, leading to increased pressure in
the condenser, which in turn increases the head pressure.
5. What is the effect of moisture inside a refrigeration
system?
A) Improves cooling efficiency
B) Enhances compressor performance
C) Leads to the formation of ice and acids
D) Increases refrigerant flow
Answer: C) Leads to the formation of ice and acids
Explanation:
, Moisture inside a refrigeration system can freeze in the
expansion valve, restricting refrigerant flow. It can also
react with refrigerants and oils to form acids, which
corrode system components.
6. What is the primary purpose of a defrost cycle in
refrigeration systems?
A) To cool the compressor
B) To prevent refrigerant leaks
C) To remove accumulated ice from the evaporator
D) To regulate refrigerant flow
Answer: C) To remove accumulated ice from the
evaporator
Explanation:
The defrost cycle is used to remove frost or ice that
accumulates on the evaporator coils, which would
otherwise reduce heat transfer efficiency and impair
system performance.
7. Which of the following methods is most commonly
used to detect a refrigerant leak?
A) Visual inspection
B) Soap bubble test
EXAM QUESTIONS 2024 ACTUAL
EXAM COMPLETE 400 QUESTIONS
WITH DETAILED VERIFIED ANSWERS
(100% CORRECT ANSWERS)
/ALREADY GRADED A+
1. What is the primary function of the evaporator in a
refrigeration system?
A) To absorb heat from the surrounding air
B) To condense refrigerant vapor into liquid
C) To compress refrigerant gas
D) To reduce the temperature of the compressor
Answer: A) To absorb heat from the surrounding air
Explanation:
The evaporator absorbs heat from the surrounding air and
uses it to evaporate the liquid refrigerant, turning it into
vapor. This phase change is essential for cooling, as it
lowers the temperature of the space being cooled.
2. Which refrigerant is commonly used in residential
air conditioning systems today?
,A) R-22
B) R-12
C) R-410A
D) R-134a
Answer: C) R-410A
Explanation:
R-410A is widely used in modern residential air
conditioning systems due to its environmental benefits
and higher efficiency compared to older refrigerants like
R-22, which has been phased out due to its ozone
depletion potential.
3. In a refrigeration system, what component is
responsible for raising the refrigerant's pressure and
temperature?
A) Evaporator
B) Condenser
C) Compressor
D) Expansion valve
Answer: C) Compressor
Explanation:
The compressor increases the pressure and temperature of
the refrigerant gas. This process is crucial because it
,allows the refrigerant to release heat when it reaches the
condenser.
4. Which of the following is a potential cause of high
head pressure in a refrigeration system?
A) Low refrigerant charge
B) Dirty condenser coils
C) Blocked expansion valve
D) Malfunctioning evaporator fan
Answer: B) Dirty condenser coils
Explanation:
Dirty condenser coils prevent the refrigerant from
releasing heat effectively, leading to increased pressure in
the condenser, which in turn increases the head pressure.
5. What is the effect of moisture inside a refrigeration
system?
A) Improves cooling efficiency
B) Enhances compressor performance
C) Leads to the formation of ice and acids
D) Increases refrigerant flow
Answer: C) Leads to the formation of ice and acids
Explanation:
, Moisture inside a refrigeration system can freeze in the
expansion valve, restricting refrigerant flow. It can also
react with refrigerants and oils to form acids, which
corrode system components.
6. What is the primary purpose of a defrost cycle in
refrigeration systems?
A) To cool the compressor
B) To prevent refrigerant leaks
C) To remove accumulated ice from the evaporator
D) To regulate refrigerant flow
Answer: C) To remove accumulated ice from the
evaporator
Explanation:
The defrost cycle is used to remove frost or ice that
accumulates on the evaporator coils, which would
otherwise reduce heat transfer efficiency and impair
system performance.
7. Which of the following methods is most commonly
used to detect a refrigerant leak?
A) Visual inspection
B) Soap bubble test
